<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <li id="demo"></li>
</body>

<script>



    function fn() {

    }
    fn.prototype = {
        say: function () { console.log('123') },
        // call: function () { console.log('abc') },
        asdasdadasda: function () { asd }
    }
    console.dir(fn)
    console.dir(demo)
    var ab = new fn()
    ab.call()

</script>

</html>